CN112154012B - Preservative composition - Google Patents

Abstract

An antimicrobial preservation system, comprising: i. itaconic acid or a salt thereof, and benzoic acid or a salt thereof.

Description

Preservative composition

Technical Field

The present invention relates to a preservative system for consumer products.

Background

The consumer product industry has a continuing need for agents with antimicrobial properties, especially for preserving otherwise perishable products (e.g., cosmetics, pharmaceuticals or foods).

A large number of antimicrobial active compounds have been used as preservative chemicals, but there is a need for alternatives that avoid possible ecological problems and are easily tolerated by the skin.

Such a preservative system should be stable, largely and preferably completely odorless, inexpensive to prepare, easy to formulate (i.e., preferably liquid), and should not be detrimental to the final product.

The present invention provides a particularly effective corrosion protection system.

Disclosure of Invention

The present invention relates to an antimicrobial preservation system comprising:

i) Itaconic acid or a salt thereof, and

ii) benzoic acid or a salt thereof.

A second aspect of the invention relates to a composition comprising the antimicrobial preservation system described above.

A third aspect of the present invention relates to a method of preserving a composition comprising the step of adding to the composition an antimicrobial preservation system comprising:

i) Itaconic acid or a salt thereof, and

ii) benzoic acid or a salt thereof.

In one embodiment of the process of the invention, the compounds i) and ii) are premixed before addition to the composition to be preserved.

In a second embodiment of the method of the invention, the compounds i) and ii) are not premixed before addition to the composition to be preserved.

Detailed Description

The present invention relates to an antimicrobial preservative system comprising itaconic acid or a salt thereof, preferably said acid.

The preservative system further comprises benzoic acid or a salt thereof. If a salt of benzoic acid is used, sodium benzoate is highly preferred.

Preferably the weight ratio of itaconic acid or salt thereof to benzoic acid or salt thereof is from 1:50 to 50:1, more preferably from 1:10 to 10:1, most preferably from 1:5 to 5:1.

In a preferred embodiment of the invention, the preservative system is included as part of the composition. Preferably, the composition is a personal care composition, more preferably the composition is a hair treatment composition.

Preferably, the total content of preservative system in the composition is 0.05-5% by weight of the total composition, more preferably 0.2-2% by weight of the total composition.

The composition of the invention comprising the preservative system of the invention preferably comprises at least 75 wt%, preferably at least 80 wt%, more preferably at least 85 wt%, most preferably at least 87 wt% water, based on the weight of the total composition.

Preferably, the composition further comprises a cationic, anionic, nonionic, zwitterionic or amphoteric surfactant or mixtures thereof.

Examples of suitable cationic surfactants that may be used include quaternary ammonium cationic surfactants corresponding to the general formula:

[N(R1)(R2)(R3)(R4)] ⁺ (X) ^-

wherein R1, R2, R3 and R4 are each independently selected from (a) aliphatic groups of 1 to 22 carbon atoms, or

(b) Aromatic, alkoxy, polyoxyalkylene, alkylamide, hydroxyalkyl, aryl or alkylaryl groups having up to 22 carbon atoms; and X is a salt forming anion such as those selected from the group consisting of halide (e.g., chloride, bromide), acetate, citrate, lactate, glycolate, phosphate, nitrate, sulfate, and alkylsulfate.

In addition to carbon and hydrogen atoms, aliphatic groups can contain ether linkages and other groups such as amino groups. Longer chain aliphatic groups, such as those having about 12 carbons or more, may be saturated or unsaturated.

Specific examples of such preferred quaternary ammonium cationic surfactants are cetyltrimethylammonium chloride (CTAC), behenyl Trimethyl Ammonium Chloride (BTAC) and mixtures thereof.

Alternatively, primary, secondary or tertiary fatty amines may be used in combination with an acid to provide cationic surfactants suitable for use in the present invention. The acid protonates the amine and forms an amine salt in situ. Thus, the amine is effectively a non-permanent quaternary or pseudo-quaternary cationic surfactant.

Suitable fatty amines of this type include amidoamines of the general formula:

R ¹ -C(O)-N(H)-R ² -N(R ³ )(R ⁴ )

wherein R is ¹ Is a fatty acid chain having 12 to 22 carbon atoms, R ² Is an alkylene radical having 1 to 4 carbon atoms, R ³ And R is ⁴ Each independently is an alkyl group having 1 to 4 carbon atoms. Stearamidopropyl dimethylamine is particularly preferred.

Examples of suitable anionic surfactants include alkyl sulphates, alkyl ether sulphates, alkylaryl sulphonates, alkanoyl isethionates, alkyl succinates, alkyl sulphosuccinates, N-alkanoyl sarcosinates, alkyl phosphates, alkyl ether carboxylates and alpha-olefin sulphonates, especially their sodium, magnesium, ammonium and mono-, di-and triethanolamine salts. Alkyl and acyl groups typically contain 8 to 18 carbon atoms and may be unsaturated. The alkyl ether sulphates, alkyl ether phosphates and alkyl ether carboxylates may contain from 1 to 10 ethylene oxide or propylene oxide units per molecule, preferably from 2 to 3 ethylene oxide units per molecule.

Examples of suitable anionic surfactants include sodium oleyl succinate, ammonium lauryl sulfosuccinate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, triethanolamine dodecylbenzene sulfonate, sodium methyl cocoyl taurate, sodium C14-16 olefin sulfonate, sodium C12/C13 alkyl polyether (path) sulfate, sodium cocoyl isethionate, sodium lauroyl isethionate and sodium N-lauryl sarcosinate. Most preferred anionic surfactants are sodium lauryl sulfate, triethanolamine monolauryl phosphate, sodium lauryl ether sulfate 1EO, 2EO and 3EO, ammonium lauryl sulfate and ammonium lauryl ether sulfate 1EO, 2EO and 3EO.

Nonionic surfactants suitable for use in the compositions of the present invention may comprise the condensation products of aliphatic (C8-C18) primary or secondary linear or branched alcohols or phenols with alkylene oxides, typically ethylene oxide, typically having from 6 to 30 ethylene oxide groups. Other suitable nonionic compounds include mono-or dialkyl alkanolamides, glycolipids preferably selected from rhamnolipids and sophorolipids. Examples include coco mono-or diethanolamide and coco monoisopropanolamide.

Amphoteric and zwitterionic surfactants suitable for use in the compositions of the present invention may include alkyl amine oxides, alkyl betaines, alkyl amidopropyl betaines, alkyl sulfobetaines (sulfobetaines), alkyl glycinates, alkyl carboxyglycinates, alkyl amphopropionates, alkyl amphoglycinates, alkyl amidopropyl hydroxysulfobetaines, acyl taurates, and acyl glutamates, wherein the alkyl and acyl groups have from 8 to 19 carbon atoms. Examples include lauryl amine oxide, cocodimethyl sulfopropyl betaine, preferably lauryl betaine, cocoamidopropyl betaine, and sodium cocoamphopropionate.

Typically, the surfactant is present in the shampoo compositions of the present invention in an amount of from 0.1 to 50% by weight, preferably from 5 to 30% by weight, more preferably from 8 to 20% by weight.

The invention will now be illustrated by the following non-limiting examples.

Examples

The concept of using fractional concentrations (Fractional Concentration) and fractional inhibitory concentrations (FIC, fractional Inhibitory Concentration) has extensively explored the different behavior of inhibitory antimicrobial agents in isolates and mixtures. See, e.g., JRW Lambert and R Lambert, j.appl. Microbiol 95,734 (2003); jadavji, CG Prober and R Cheung, antimicrobial Agents and Chemotherapy 26,91 (1984), and WO 2004/006876. These parameters may be defined as follows:

FC (component a) =concentration/MIC of component a tested in mixture (component a tested as single active substance)

FIC (component a) =mic (component a tested in mixtures)/MIC (component a tested as a single active substance)

The interaction between the antimicrobial agents may be additive, synergistic, or possibly antagonistic, depending on whether the potency of the combination is equal to, greater than, or less than the potency obtained at the same total concentration of the individual components when tested alone.

These relationships can be expressed mathematically by summing the fractional MIC values of all the components present in the mixture to give a "fractional inhibition index":

∑FIC＝FIC _{(component 1)} +FIC _{(component 2)}

Such that:

sigma FIC > 1 corresponds to additive or antagonistic activity

Sigma FIC <1 corresponds to synergistic activity

One comparable approach is to calculate a Synergy Index (SI), which is Kull, f.c.; eisman, p.c.; a commercially acceptable method is described by Sylwestrowicz, H.D. and Mayer, R.L., in Applied Microbiology 9:538-541 (1961).

Liquid broth assays (MIC and checkerboard) were performed to determine the minimum concentration of single and binary combinations of preservative chemicals. Modified methods of ISO 20776-1:2006 were used for the following screening. By 1-5X 10 ⁶ Microbial inoculation corrosion protectionStock solutions of chemicals and trypsin soybean broth and incubated at 30℃for 24 hours, after which OD was measured ₆₀₀ Optical density at nm. Microorganisms used for evaluation include gram-negative non-fermenting bacteria: pseudomonas aeruginosa, pseudomonas putida&Burkholderia cepacia and gram-negative fermenting bacteria: enterobacter Rigous&Klebsiella species. MIC was defined as where observed compared to positive growth control without preservative chemical<Concentration of 25% growth. Preservative chemicals were screened at a concentration range of 0.0156-2%.

Table 1: minimum inhibitory concentration of individual chemicals

Table 2: fractional inhibitory concentration of itaconic acid chemical combinations on microbial pools

Table 3: fractional inhibitory concentrations of itaconic acid and sodium benzoate at different ratios

The above table demonstrates the effectiveness of the composition according to the invention as a preservative.

Claims (8)

1. A personal care composition comprising an antimicrobial preservation system, the antimicrobial preservation system comprising:

i. itaconic acid or a salt thereof, and

benzoic acid or a salt thereof,

the composition comprises at least 75% by weight of water, based on the weight of the total composition.

2. The composition of claim 1, wherein the weight ratio of compound i) to compound ii) is from 1:50 to 50:1.

3. The composition according to any of the preceding claims, wherein the weight ratio of compound i) to compound ii) is 1:10-10:1.

4. The composition of claim 1 wherein the preservative system is present in an amount of 0.05 to 5% by weight of the total composition.

5. The composition of claim 1 which is a hair treatment composition.

6. A method of preserving a personal care composition comprising the step of adding to the composition an antimicrobial preservation system comprising:

i. itaconic acid or a salt thereof, and

benzoic acid or a salt thereof,

the composition comprises at least 75% by weight of water, based on the weight of the total composition.

7. The process according to claim 6, wherein the compounds i) and ii) are premixed before addition to the composition to be preserved.

8. The method of claim 6, wherein compounds i) and ii) are not premixed prior to addition of the composition to be preserved.